The wire (both the thinner wire, used for wrapping, and the thicker wire in the frame) has been treated to be anti-tarnish. This will keep the copper from greening your skin, too. However, this coating can wear off after time. You can prolong the life and beauty of your jewelry by keeping it away from water, soaps, detergents, lotions, sunscreens, and perfume. If the coating starts to wear off, it can be sealed again with a coat of clear fingernail polish.